桓台县高产农田土壤硝态氮淋失动态研究  

The dynamics of nitrate nitrogen leaching through soil in high-yield farmland ecosystem.

作　　者：刘光栋[1] 吴文良[1] 

机构地区：[1]中国农业大学资源与环境学院,北京100094

出　　处：《中国生态农业学报》2002年第4期71-74,共4页Chinese Journal of Eco-Agriculture

基　　金：国家自然科学基金重点资助项目(39630070)部分研究内容

摘　　要：试验研究高产农田生态系统条件下N肥施用量和秸秆还田对土体硝态氮(NO_3^--N)的时空分布动态结果表明,NO_3^--N含量在空间上随土壤深度而降低,这一相关关系可用Y=aX^b函数表达。小麦-玉米2季秸秆还田同单季小麦秸秆还田对NO_3^--N的动态影响较小,但相同施N量下未进行玉米秸秆还田0～40cm土层土壤中NO_3^--N含量偏高,土体NO_3^--N有淋失较强的趋势。土体NO_3^--N含量年度内波动大小与施N量密切相关,0～40cm土层土壤内NO_3^--N含量起伏最大,60cm土层以下相对稳定。各土层内NO_3^--N含量与施N量相关密切,这一相关关系影响到2m土层深度。土体中NO_3^--N含量周年内出现2次峰值和1次低谷,峰值出现在玉米和小麦收获后,低谷发生在小麦苗期～开花期土体养分大量吸收时期。9月下旬2m土层土壤NO_3^--N含量可高达10mg/kg,而且有淋失出2m土体的趋势。In the high yield farmland ecosystem, the dynamics of nitrate nitrogen distribution in soil profile influenced by nitrogen fertilization and crop straw returning practice is studied by field plot experiment. At a certain nitrogen rate, the content of NO3--N decreases with depth, which can be regressively described as a power function Y = aXb. Though little difference is made between the crop straw returning patterns of either wheat-corn and wheat alone,more nitrogen leaching tends to occur in the later practice since more nitrate nitrogen have been accumulated within 0-40cm soil layer. Soil content of NO3--N reaches the summits twice and the valley once in a year. The summits turn up after harvest stages of corn and wheat and the valley lasts from wheat seedling in spring to flowering, when wheat shows the maximum uptake of available nutrient from soil body. Content of NO3--N fluctuates most within 0 - 40cm layer and almost keeps stable below 60cm depth. The fluctuation of content of NO3--N within the observed year through soil profile as deep as two meters is closely correlated with the rate of nitrogen applied. Until the end of September after raining season, content of NO3--N is up to 10mg/kg. It is therefore predicted that under the conditions of present farmland ecosystem soil nitrogen is leached not only to two meters depth but also out of two meters soil body.

关 键 词：桓台县 高产农田 山东 土壤硝态氮淋失 动态研究 

分 类 号：S152.61[农业科学—土壤学]